The interfacial properties of the organic fraction of biomass burning aerosols (BBA), such as the critical micelle concentration (CMC) and surfactant composition, may vary based on the origin and moisture content of the fuel and the resulting combustion conditions. Surfactant composition, fraction of total particle mass, surface tension minimums, and CMC values of organics extracted from fresh and aged BBA produced using fuel beds from Georgia ecoregions (Piedmont, Coastal Plain, and Blue Ridge) and with fuel moisture contents representative of prescribed fires or drought-induced wildfires were measured using high resolution mass spectrometry, UV-vis spectroscopy, and pendant drop tensiometry. Surface tension minimums of organics extracted from all BBA were low (<
45 mN m